Recording and reproducing means



Aug. 24, 1937. BENbER 2,090,957 RECORDING AND REPRODUCING MEANS Original Filed Jaii. 26/1932 2 sheets-Sheet l INVENTOR Mar 59/1 a er BY $1 ATTORNEY Aug. 24, 1937. 'M. BENDER RECORDING AND REPRODUCING MEANS Original Filed Jan. 26, l932 2 Sheets-Sheet; 2

INVENTOR Max Benn/er RA ATTORNEY Patented Aug. 24, 1937 UNITED STATES PATENT OFFICE mesne assignments, to United Acoustigraph Corporation, a corporation of Nevada Application January 26, 1932, Serial No. 588,958 Renewed January 21, 1937 16 Claims. :1. 179-100.41

This invention relates to recording and reproducing of sound and one object of the invention is to provide an improved method and apparatus for recording sound in the form of a hill and dale groove on a relatively hard flexible material such as a film of celluloid.

A further object of my invention is to provide an improved method and apparatus for forming a plurality of sound grooves simultaneously. A further object of my invention is to provide an improved recording device and method of recording on a plurality of separate films simultaneously.

In this manner, for example, when the device is used for dictating correspondence in the form -of a film record, one of the records may be sent and a copy retained.

In the recording of sound on film by forming a hill and dale record groove difiiculty has been experienced in imparting to the recording tool the requisite motion for forming a sound groove with symmetrical or undistorted undulation. This is due largely to the fact that the resistance offered by the record material to the cutting tool when moving into the film is different from the resistance encountered when moving out of record. This is particularly true when the material is relatively hard such as a photographic film. To avoid this difficulty in the embodiment of the invention herein disclosed, I provide a recording apparatus which embodies two cutting tools with means for vibrating these tools simultaneously but also in opposite directions whereby one tool is moving into the film the other tool is moving in a direction out of the film. By this means the resistance offered to the vibratory movement is more uniform.

A further object of the invention is to provide, in an improved recording apparatus of the char- 'acter above described, a novel means for reproducing the sound.

Other objects of my invention will appear from the following description taken in connection with the accompanying drawings wherein:

Figure 1 is a side elevation of an improved recording and reproducing device embodying one form of invention and showing the .device in 1 operative engagement with a film supported by a stationary anvil;

Figure 2 is a bottom plan view of the recording 5 'device shown in Figure 1 and showing the duplicate members actuated from this single electromagnet;

Figure 3 is a sectional view taken on the line 3-3 of Figure 1, certain of the parts being shown 5in elevation, and showing the device operatively engaging two films adapted to move side by side over the anvil;

Fig. 4 is a sectional view taken on the line 4--4 of Figure 3, certain of the parts being shown in elevation;

Figure 5 is a detail perspective viewof' one of the resilient supporting members for holding a cutting and a reproducing stylus; I

Figure 6 is a perspective view of the armature for operating the styluses and spaced from the armature for the sake of clearness, a spring actuated means for pressing the armature upward into firm contact with its bearings so as to avoid. any lost motion between thearmature and bearings; and

Figure 7 is a sectional view, partly in elevation, taken on the line 1-1 of Figure 1.

Referring to Figures 1 to 40f the drawings, l0 represents an electro-magnetic device which is designed to function as an electrO-magnetic recorder and reproducer. This device has two cutting or impressing styluses l l for forming largely hill and dale sound record grooves on a pair of films l2 adapted to be moved side by side over an are or an anvil l3 or by any appropriate means not shown, The styluses I l are designed to vibrate in a vertical plane, one always moving in direction opposite to the other as will more clearly appear hereafter.

The electro-magnetic recorder I0 comprises a frame I6 a portion of which forms the core of an electro-magnet Il comprising a coil l8 adapted to be supplied with current from a source of constant potential so as to create a uniform mag netic field. Reference characters 20 represent pole pieces of the magnet of which there are two upper and two lower, opposed to one another as shown in Figures 1 and 3. These pole pieces are adjustably secured to the magnetic frame so that the air gaps between each pole piece and the armature may be varied as desired. Mounted on each of the pole pieces is a coil 22 designed to carry current which is varied in accordance with the variations of the sound to be recorded and mounted to vibrate about its central transverse axis is the armature 23 carried on adjustable pivot bearings 24 and 25 secured in the frame I6. As shown in Figure 3 the armature extends outwardly between opposing pole pieces at opposite sides of the axis.

In order to maintain the armature in firm contact with its bearings and so prevent any lost motion which might cause distortion of the record I employ a means engaging the armature along its pivotal axis, for pressing the armature upwardly into contact with its bearings. As is more plainly shown in Figure 6 the armature is formed with a V-shaped groove 26 located at and extending along the pivotal axis and this groove is adapted to receive the upper knife edge 28 of a pressure member 29 of approximately T-shaped in cross section and formed with downwardly extending lugs 39 around which are seated respectively the upper portions of the helical springs 3|. The lower portions of the springs 3i embrace and are held in position by removable studs 33 set in recesses 34 in the lower portion of the frame It. The springs 3| are sufficient force to maintain the armature in firm contact with the lower sides of the pivotal bearings throughout the vibration of the armature. Opposite ends of the armature 23 are formed with openings 37 through which extend connecting rods 38 each of which, in the present form of my invention, are rigidly secured to the armature by clamping nuts 39 above'and below the openings 3'! (see Figure 4). These rods may be of any suitable material but preferably of phosphor bronze. The rods 38 extend downwardly through openings 49 in the frame it and terminate in end pieces 42 adapted to embrace and be secured to lugs 43 formed in enlarged central portions 45 of elongated stylus-carrying members 44.

As shown in Figure the member 44 has outwardly tapered ends and its central portion 45 is formed with a recess 46 in which is located the lug 43. The member 44 is preferably formed of light resilient material such as dural alumimum and its outer ends form resilient strips 4'! the outer ends of which are clamped by means of set screws in recesses 48 formed in downward extensions 59 of the frame 16. Central portion 35 of the member 44 has a downwardly inclined opening 52 therethrough which terminates in a V-shaped groove designed to receive the upper side of the shank 55 of the cutting stylus ll. The shank 55 is held firmly in position in the groove 53 by a rod 56 which extends through the opening 52 and is screwthreaded to receive a tightening nut 51.

When it is desired to employ the apparatus for reproducing as well as recording I may support a reproducing stylus 6k] in an opening Si in the central portion 45 of the member 44, this stylus being held in position in the opening by, a set screw 62.

Reference character 63 represents a counterbalanced supportdesigned to hold the recording and reproducing device in operative contact with the film. The frame l6 of the device is secured to the support 63 by bolts 54 which, if desired, may be movable in slots so that the recorder may be moved to bring either the recording or reproducing stylus into operative engagement with the film.

If desired, the support for the frame IS, instead of being counter-balanced, so as to permit rocking movement of the recording device may be fixed and so spaced with respect to thefixed anvil 53 as to provide the requisite cutting engagement of the stylus with the moving film.

From the above description it will be seen that when the coils 22 are energized by varying sound currents, the armature will be vibrated, rocking about its central pivotal axis. This motion will be communicated through the connectingrods 38 to the central portions 45 of the members 44, one moving up as the other moves down. In this manner the recording stylus is. vibrated and the resilient strips 41 which form the ends of the member 44 and which are clamped rigidly to the frame I6 provide a cushioning, damping or resisting of the vibration of the armature and parts. It is generally desirable that this resistance be greater in the case of recording than when reproducing and when employing the device for reproducing I preferably may, if desired, loosen the screws 48 which clamp one of the members 44 to the frame and employ only the reproducing stylus carried by the other memher in which way the damping effect for reproduction is considerably reduced.

By reference to Figure 3 it will be seen that a record is made on two films l2 which are drawn side by side over the anvil. In this case the armature 23 is made of such length that the recording styluses are spaced a distance apart somewhat greater than the width of the film. When it is desired to form the two grooves on a single film, the armature may be made shorter so as'to permit a closer spacing of the recording styluses.

Having now described my invention what I claim and desire to secure by Letters Patent is:

1. In a device for recording sound in the form of hill and dale grooves, a pair of recording styluses, pivoted actuating means, and means at opposite sides of the pivotal axis of said first named means for actuating said styluses in opposite directions with respect to the record.

2. In a device for recording and reproducing sound, an actuating means, a recording and a reproducing stylus operatively connected to said means, means for resisting movement of said styluses and adjusting means for varying such resistance.

3. In a device for recording and reproducing sound, an actuating means, a cutting and a reproducing stylus operatively connected with said means, shifting means for causing one or theother of said styluses to engage a record body, means for resisting movement of said styluses and means for changing such resistance from a value for use with a recording stylus to a value for use with said reproducing stylus.

4. In an electro-magnetic sound recording device, a frame, means for creating a permanent magnetic field, means for varying said field in accordance with sound to be recorded, an armature pivotally mounted in bearings on said frame;-

a stylus connected to said armature and resilient means for holding the armature in firm contact with said bearings.

5. In an electro-magnetic sound recording device, a frame, means for creating a permanent magnetic field, means for varying said field in accordance with sound to be recorded, an armature pivotally mounted in bearings on said frame, a stylus connected to said armature and resilient means engaging said armature along its pivotal axis.

6. In a sound recording device, a frame, a

stylus, a metal holding member having ends formed of resilient material, secured to said frame and formed with an enlarged non-resilient rela-" tively thick intermediate portion and thin resilient ends of substantially less cross sectional area than the intermediate portion and means for securing said stylus to said intermediate portion and said ends to said frame.

7. In a sound recording device, an actuating element, a stylus, a holding device therefor comprising an elongated member tapered toward its opposite ends to form thin resilient strips with a non-resilient thick intermediate portion and being formed at said portion with means for connecting said actuating element thereto and for holding said stylus at an acute angle to said member with the point of the stylus in alignment with the actuating element.

8. In an electro-magnetic sound recording device, a frame, means for creating a constant magnetic field, means for varying the field in accordance with the sound to be recorded, an armature pivotally mounted in said field, a pair of recording styluses, elongated stylus-supporting members arranged side by side and formed with resilient ends rigidly secured to said frame and actuating connections between said members and said armature at opposite sides of the pivotal axis of said armature, for moving said styluses in opposite directions.

9. In a device for cutting sound grooves in record material, a pair of recording styluses arranged side by side and having their axes parallel to and displaced from one another, actuating means therefor and connections between said means and styluses for actuating them in opposite directions with respect to said material.

10. In a device for recording a plurality of sound grooves, a pair of styluses, an actuating member pivotally mounted between its ends, connections between said styluses and said member respectively at points adjacent said ends and means for moving said member in accordance with sound to be recorded.

11. In a. device for recording sound, a pair of recording styluses, electromagnetic means comprising a pivoted armature and connections between said styluses and armature at opposite sides of the pivotal axis of the armature for actuating said styluses simultaneously in opposite directions.

12. In a device for forming sound grooves, a pair of recording styluses, a connection between said styluses comprising a pivoted means connected to the respective styluses at points at opposite sides of the pivotal axis, and actuating means for said styluses, the parts being so constructed and arranged the said actuating means serves to move said styluses simultaneously in opposite directions.

13. In an electromagnetic recording device, a supporting frame, a stylus holder having resilient ends rigidly attached to said frame, a magnet supported by said frame, an armature for said magnet, pivotally mounted in bearings in said frame, resilient means engaging said armature for maintaining the armature in firm contact with said bearings and an operating connection between armature and a point of said holder intermediate its ends.

14. In a device of the class described, means creating a permanent magnetic field, opposed magnetic coils in said field, an armature for said coils pivotally mounted in bearings, resilient means for maintaining said armature in firm contact with said bearings and a stylus connected to said armature.

15. In a device of the class described, means creating a permanent magnetic field, opposing magnetic coils in said field, an armature for said coils, pivoted in bearings at opposite ends, and formed with a bearing surface extending between the bearings, means for maintaining said armature in firm contact with said bearings, said means comprising a member adapted to engage said bearing surface and resilient means pressing said surface, and a stylus operatively connected with said armature.

16. In a device for recording hill and dale sound grooves in a flexible film, a supporting frame adapted to be positioned above the film, means carried by said frame for creating a permanent magnetic field, opposing magnetic coils in said field, an armature for said coils pivoted in bearings at opposite ends and formed at its bottom with a bearing surface extending between the bearings, means for maintaining said armature in firm contact with the upper bearing surface of said bearings, said last named means comprising a member resiliently pressed upwardly against said surface between the bearings and a stylus operatively connected with said armature.

MAX BENDER. 

